diff --git a/classes/db/DB.class.php b/classes/db/DB.class.php
index 042cc8986..6db31fa3a 100644
--- a/classes/db/DB.class.php
+++ b/classes/db/DB.class.php
@@ -305,6 +305,7 @@
 
             require_once(_XE_PATH_.'classes/xml/xmlquery/DBParser.class.php');
             require_once(_XE_PATH_.'classes/xml/xmlquery/argument/Argument.class.php');
+            require_once(_XE_PATH_.'classes/xml/xmlquery/argument/SortArgument.class.php');
             require_once(_XE_PATH_.'classes/xml/xmlquery/argument/ConditionArgument.class.php');
             require_once(_XE_PATH_.'classes/xml/XmlQueryParser.class.php');
             require_once(_XE_PATH_.'classes/db/queryparts/expression/Expression.class.php');
diff --git a/classes/xml/xmlquery/tags/navigation/IndexTag.class.php b/classes/xml/xmlquery/tags/navigation/IndexTag.class.php
index 6e1dd553e..c3698ad59 100644
--- a/classes/xml/xmlquery/tags/navigation/IndexTag.class.php
+++ b/classes/xml/xmlquery/tags/navigation/IndexTag.class.php
@@ -14,7 +14,7 @@
 			//$dbParser = XmlQueryParser::getDBParser();
 			//$index->attrs->default = $dbParser->parseExpression($index->attrs->default);
 			$this->default = $index->attrs->default;
-			require_once(_XE_PATH_.'classes/xml/xmlquery/queryargument/QueryArgument.class.php');
+			require_once(_XE_PATH_.'classes/xml/xmlquery/queryargument/SortQueryArgument.class.php');
 			$this->argument = new QueryArgument($index);
 
                         // Sort order - asc / desc